As power systems integrate increasing shares of variable renewable energy, hydropower and other synchronous generators are being asked to operate in increasingly demanding conditions. More frequent start-stop cycles, operation closer to capability limits and increased excitation requirements can place additional stress on generating units and accelerate their ageing.
This challenge was at the heart of a paper presented by researchers from the Nikola Tesla Institute of Electrical Engineering, University of Belgrade, together with experts from Elektroprivreda Srbije (EPS)and other Serbian partners at CIGRE 2026.
The paper, “Stress-Aware Maintenance Intelligence System (SAMIS) of Synchronous Generators”(A1_12331_2026), presents a new approach to monitoring and managing the cumulative operational stress experienced by synchronous generators.
From operational flexibility to asset integrity
SAMIS combines an electro-thermal digital twin, operational stress tracking, consistency assessment and structured human observations to transform operational data into decision-relevant information for maintenance and operation.
Importantly, the approach was validated using real operational data from hydrogenerators. The results show that SAMIS can identify latent stress conditions before conventional alarms are triggered, distinguish physical degradation from measurement bias, and detect reduced thermal margins even when monitored parameters remain within standard operating limits.
This research addresses a challenge closely connected to SE-HYDRO’s ambition: how can hydropower plants provide greater flexibility to support the energy transition while effectively monitoring and managing the stresses on their generating equipment?
While SE-HYDRO is developing new approaches to make hydropower operation more flexible while integrating environmental and societal considerations, SAMIS provides an important complementary perspective on the physical consequences of increased operational flexibility. Understanding and anticipating operational stress is essential if hydropower units are to safely respond to the changing needs of renewable-based power systems.
About SE-HYDRO partners
Researchers from the Nikola Tesla Institute contribute cutting-edge expertise in power generation and electrical engineering, while EPS is SE-HYDRO’s partner responsible for the Serbian pilot.
Together, these developments illustrate the broader challenge behind the future of flexible hydropower: innovation must address not only how plants interact with energy markets, ecosystems and communities, but also how their physical assets can safely withstand new operating regimes.
Congratulations to our partners and authors for bringing this important work to the international CIGRE community!
Read more about the paper:
Stress-Aware Maintenance Intelligence System (SAMIS) of Synchronous Generators
